1. Field of the Invention
The present invention relates to mixtures and compositions suitable for controlling Hylotrupes bajulus and Pyrrhidium sanguineum and their use for this purpose.
2. Description of the Background Art
In cases in which the control of insect pests using conventional insecticides is not indicated, for example in the treatment of structural timber in residential buildings, there is great interest in a biological pest control which can be selectively directed against a single type of pest or a small group of pests.
Methods of pest control in which the sex attractants or pheromones (attractants in the following) of the particular pests are used are generally known (cf. DE-A 36 03 377 [control of the vine moth] or WO-A 93/08148 [control of the cobbling moth]).
Especially Hylotrupes bajulus and in addition Pyrrhidium sanguineum are important wood pests, because their larvae bore into wood and destroy it.
Hylotrupes bajulus and Pyrrhidium sanguineum belong to the Cerambycidae family (round-headed borers), in which the involvement of attractants in mating behavior has already been studied for a long time. Contact pheromones or pheromones which act at short distances (short-range pheromones) have already been found in females of various round-headed borer species (cf. USDA Forest Service Research Note NE-240, 1 (1977); Appl. Ent. Zool. 27 (1992), page 489; J. Chem. Ecol. 18 (1992), page 245; ibid., 19 (1993), page 2347). In the case of Hylotrupes bajulus, it was suspected that the females form an attractant on their elytra which is used for finding a mate.
There is a study on an attractant which is released by the males (cf. Chem. Lett. (1984), page 263; Appl. Ent. Zool. 17 (1982), page 497; ibid. 21 (1986), page 606).
As a rule, from economic points of view it makes little sense for pest control to isolate the natural attractants from the pests producing them, because they are only there in low concentration. Instead of this, the search is aimed mostly at synthetically produced natural substances, or synthetic substances structurally related to these.